I know which version I want. How do I install it?

The 64-bit version of Office is automatically installed unless you explicitly select the 32-bit version before beginning the installation process.

To install either the 32 or 64-bit version of Office 365 or Office 2019, follow the steps in Install Office on a PC.

Important: If you install the 64-bit version, but want the 32-bit version instead, you must first uninstall the 64-bit version before installing the 32-bit version. The same is true if you installed the 32-bit version, but want to install the 64-bit version. See “Office (64-bit or 32-bit) couldn’t be installed” error.

If you're still not sure which version, 32-bit or 64-bit is a better choice for you, see the section below.

Reasons to choose the 64-bit version

Computers running 64-bit versions of Windows generally have more resources such as processing power and memory, than their 32-bit predecessors. Also, 64-bit applications can access more memory than 32-bit applications (up to 18.4 million Petabytes). Therefore, if your scenarios include large files and/or working with large data sets and your computer is running 64-bit version of Windows, 64-bit is the right choice when:

You’re working with extremely large pictures, videos, or animations in PowerPoint. The 64-bit version of Office may be better suited to handle these complex slide decks.

You’re working with files over 2 GB in Project, especially if the project has many sub-projects.

You’re developing in-house Office solutions like add-ins or document-level customization. Using the 64-bit version of Office lets you deliver a 64-bit version of those solutions as well as a 32-bit version. In-house Office solution developers should have access to the 64-bit Office 2016 for testing and updating these solutions.

You’re working with the Large Number data type in Access, and while this data type is supported by 32-bit Access, you may see unexpected results when executing code or expressions that use native 32-bit VBA libraries. 64-bit VBA provides the LongLong data type which fully supports large numbers. For more information, see Using the Large Number data type.

Tip: If you have 64-bit operating system with an x64-based processor, you can choose to install 32-bit or 64-bit Office.

IT Professionals and developers in particular, should also review the following situations where the 32-bit version of Office is still the best choice for you or your organization.

You have 32-bit COM Add-ins with no 64-bit alternative. You can continue to run 32-bit COM add-ins in 32-bit Office on 64-bit Windows. You can also try contacting the COM Add-in vendor and requesting a 64-bit version.

You use 32-bit controls with no 64-bit alternative. You can continue to run 32-bit controls in 32-bit Office like Microsoft Windows Common Controls (Mscomctl.ocx, comctl.ocx), or any existing 3rd-party 32-bit controls.

Your VBA code uses Declare statements Most VBA code doesn’t need to change when using in 64-bit or 32-bit, unless you use Declare statements to call Windows API using 32-bit data types like long, for pointers and handles. In most cases, adding PtrSafe to the Declare and replacing long with LongPtr will make the Declare statement compatible with both 32- and 64-bit. However this might not be possible in rare cases where there is no 64-bit API to Declare. For more information about what VBA changes are needed to make it run on 64-bit Office, see 64-Bit Visual Basic for Applications Overview.

You have 32-bit MAPI applications for Outlook. With a growing number of 64-bit Outlook customers, rebuilding 32-bit MAPI applications, add-ins, or macros for 64-bit Outlook is the recommended option, but if needed you can continue to run them with 32-bit Outlook only, as well. To learn about preparing Outlook applications for both 32-bit and 64-bit platforms, see Building MAPI Applications on 32-Bit and 64-Bit Platforms and the Outlook MAPI Reference.

You’re activating a 32-bit OLE server or object. You can continue to run your 32-bit OLE Server application with a 32-bit version of Office installed.

You're using SharePoint Server 2010 and you need the Edit in Datasheet view. You can continue to use the Edit in Datasheet view functionality in SharePoint Server 2010 with 32-bit Office.

You need 32-bit Microsoft Access .mde, .ade, and .accde database files. While you can recompile 32-bit .mde, .ade, and .accde files to make them 64-bit compatible, you can continue to run 32-bit .mde, .ade, and .accde files in 32-bit Access.

You require Legacy Equation Editor or WLL (Word Add-in libraries) files in Word. You can continue to use Legacy Word Equation Editor and run WLL files in 32-bit Word.

You have an old embedded media file in your PowerPoint presentation with no available 64-bit codec.

Ready to install?

To install either the 32 or 64-bit version of Office 365 or Office 2019, follow the steps in Install Office on a PC.

I know which version I want. How do I install it?

The 32-bit version of Office is automatically installed unless you explicitly select the 64-bit version before beginning the installation process.

If you're still not sure which version, 32-bit or 64-bit is a better choice for you, see the section below.

Reasons to choose the 64-bit version

Computers running 64-bit versions of Windows generally have more resources such as processing power and memory, than their 32-bit predecessors. Also, 64-bit applications can access more memory than 32-bit applications (up to 18.4 million Petabytes). Therefore, if your scenarios include large files and/or working with large data sets and your computer is running 64-bit version of Windows, 64-bit is the right choice when:

You’re working with extremely large pictures, videos, or animations in PowerPoint. The 64-bit version of Office may be better suited to handle these complex slide decks.

You’re working with files over 2 GB in Project, especially if the project has many sub-projects.

You’re developing in-house Office solutions like add-ins or document-level customization. Using the 64-bit version of Office lets you deliver a 64-bit version of those solutions as well as a 32-bit version. In-house Office solution developers should have access to the 64-bit Office 2016 for testing and updating these solutions.

You’re working with the Large Number data type in Access, and while this data type is supported by 32-bit Access, you may see unexpected results when executing code or expressions that use native 32-bit VBA libraries. 64-bit VBA provides the LongLong data type which fully supports large numbers. For more information, see Using the Large Number data type.

Reasons to choose the 32-bit version

Tip: If you have 64-bit operating system with an x64-based processor, you can choose to install 32-bit or 64-bit Office.

IT Professionals and developers in particular, should also review the following situations where the 32-bit version of Office is still the best choice for you or your organization.

You have 32-bit COM Add-ins with no 64-bit alternative. You can continue to run 32-bit COM add-ins in 32-bit Office on 64-bit Windows. You can also try contacting the COM Add-in vendor and requesting a 64-bit version.

You use 32-bit controls with no 64-bit alternative. You can continue to run 32-bit controls in 32-bit Office like Microsoft Windows Common Controls (Mscomctl.ocx, comctl.ocx), or any existing 3rd-party 32-bit controls.

Your VBA code uses Declare statements Most VBA code doesn’t need to change when using in 64-bit or 32-bit, unless you use Declare statements to call Windows API using 32-bit data types like long, for pointers and handles. In most cases, adding PtrSafe to the Declare and replacing long with LongPtr will make the Declare statement compatible with both 32- and 64-bit. However this might not be possible in rare cases where there is no 64-bit API to Declare. For more information about what VBA changes are needed to make it run on 64-bit Office, see 64-Bit Visual Basic for Applications Overview.

You have 32-bit MAPI applications for Outlook. With a growing number of 64-bit Outlook customers, rebuilding 32-bit MAPI applications, add-ins, or macros for 64-bit Outlook is the recommended option, but if needed you can continue to run them with 32-bit Outlook only, as well. To learn about preparing Outlook applications for both 32-bit and 64-bit platforms, see Building MAPI Applications on 32-Bit and 64-Bit Platforms and the Outlook MAPI Reference.

You’re activating a 32-bit OLE server or object. You can continue to run your 32-bit OLE Server application with a 32-bit version of Office installed.

You're using SharePoint Server 2010 and you need the Edit in Datasheet view. You can continue to use the Edit in Datasheet view functionality in SharePoint Server 2010 with 32-bit Office.

You need 32-bit Microsoft Access .mde, .ade, and .accde database files. While you can recompile 32-bit .mde, .ade, and .accde files to make them 64-bit compatible, you can continue to run 32-bit .mde, .ade, and .accde files in 32-bit Access.

You require Legacy Equation Editor or WLL (Word Add-in libraries) files in Word. You can continue to use Legacy Word Equation Editor and run WLL files in 32-bit Word.

You have an old embedded media file in your PowerPoint presentation with no available 64-bit codec.

Ready to install?

There are two versions of Office 2013 available for installation, 32-bit and 64-bit. We recommend the 32-bit version of Office for most users, because it’s more compatible with most other applications, especially 3rd-party add-ins. However, consider the 64-bit version, especially if you're working with large blocks of information or graphics.

If you're still not sure which is a better choice for you, see the sections below.

Reasons to choose the 64-bit version

The 64-bit version of Office has some limitations; however it is a good choice when:

You work with extremely large data sets, like enterprise-scale Excel workbooks with complex calculations, many pivot tables, connections to external databases, and using Power Pivot, Power Map, or Power View. The 64-bit version of Office may perform better for you.

You work with extremely large pictures, videos, or animations in PowerPoint. The 64-bit version may be better suited to handle these complex slide decks.

You work with extremely large Word documents. The 64-bit version might be better suited to handle Word documents with large tables, graphics, or other objects.

You’re working with files over 2 gigabytes (GB) in Project 2013, especially if the project has several sub-projects.

You want to keep the 64-bit version that you’re already using. The 32-bit and 64-bit versions of Office programs aren’t compatible, so you can’t install both on the same computer.

Your organization requires that Hardware Data Execution Prevention (DEP) be enforced for Office applications. DEP is a set of hardware and software technologies that some organizations use to enhance security.

If none of these situations apply to you, the 32-bit version is most likely a better choice.

Note: The 32-bit version of Office works well with both the 32-bit and 64-bit versions of Windows. If you’re installing the 64-bit version of Office, you need the 64-bit version of Windows. If you’re not installing on Windows, you don’t need to be concerned about 32-bit or 64-bit options. To determine how to tell what version of Office you're using, go to What version of Office am I using.

If you decide to switch from 32-bit Office to 64-bit Office, you must uninstall the 32-bit version first, and then install the 64-bit version.

Reasons to choose the 32-bit version

The 64-bit version of Office may perform better in some cases, but you need to know about limitations.

If you have 64-bit operating system with an x64-based processor, you can choose to install 32-bit or 64-bit Office.

IT Professionals and developers in particular, should look at the following situations, and review the linked overviews. If these limitations would affect you, the 32-bit version would be a better choice.

Solutions that use ActiveX controls library. ComCtl controls won’t work. There are several ways for developers to work around this and provide a 64-bit solution.

32-bit third party ActiveX controls and add-ins won’t work. The vendor would need to create 64-bit versions of these controls.

Visual Basic for Applications (VBA) that contain Declare statements won’t work in the 64-bit version of Office without being updated. For more information about what VBA changes are needed to make it run on 64-bit Office, see 64-bit Visual Basic for Applications Overview.

Compiled Access databases, such as .MDE, .ADE, and .ACCDE files won’t work unless they’re specifically written for the 64-bit version of Office.

The legacy Equation Editor in Word isn’t supported on 64-bit Office 2016, but the equation builder feature in Word 2013 is supported on all platforms. Also, Word Add-in Libraries (WLL) are not supported in 64-bit Office 2013.

If you have specific add-ins that you use in the 32-bit version of Office, they might not work in 64-bit Office, and vice versa. If you’re concerned, check your current version of Office before installing the new one. Consider testing the add-in with 64-bit Office, or finding out if a 64-bit version of the add-in is available from the developer.

Important: If you’re an administrator who is deploying Office, we have more 64-bit technical info available on TechNet at 64-bit editions of Office 2013.

Ready to install?

Office 2010 was the first release where Office offered both 32-bit and 64-bit versions. The 32-bit version is Office is installed automatically. However, the version that’s right for you depends on how you plan to use Office. If you have specific add-ins that you use in the 32-bit version of Office, they might not work in 64-bit Office and vice versa. If you’re concerned, check your current version of Office before installing the new one. Consider testing the add-in with 64-bit Office, or checking if a 64-bit version of the add-in is available from the vendor/developer.

I know I want the 64-bit version. How do I install it?

If you're still not sure which is a better choice for you, see the sections below.

Reasons to choose the 64-bit version

The benefits of using the 64-bit version of Office 2010 are listed below, and there are a few limitations such as not working well with some older version add-ins. It’s mostly because of the limitations that the 32-bit version is installed automatically (by default), even on the 64-bit Windows operating system.

If your work scenarios include very large files and/or working with large sets of data, and your computer is running the 64-bit version of Windows, 64-bit is the right choice specifically when:

You’re working with very large data sets, such as enterprise-scale Office Excel workbooks with complex calculations, lots of pivot tables, connecting to external databases, and using features such as Power Pivot, 3D Map, Power View, or Get & Transform. Because 64-bit Office doesn’t impose specific limits on file size, as 32-bit Office does (2 gigabyte (GB) limit), it may work better with large data sets.

You’re working with extremely large pictures, videos, or animation in Office PowerPoint. The 64-bit version of Office may be better suited to handle these complex slide decks.

You’re working with files that take up over 2 gigabytes of space in Office Project, especially if the project has many sub-projects.

Your organization requires that Hardware Data Execution Prevention (DEP) be enforced for Office applications. DEP is a set of hardware and software technologies that some organizations use to enhance security. For 64-bit installations DEP will always be enforced, while on 32-bit installations DEP needs to be configured through settings.

With more Outlook customers using 64-bit, rebuilding 32-bit Messaging Application Programming Interface (MAPI) applications, add-ins, or macros for 64-bit Outlook is the recommended option. But if necessary you can also continue to run them with 32-bit Outlook only.

Reasons to choose the 32-bit version

If you have 64-bit operating system with an x64-based processor, you can choose to install 32-bit or 64-bit Office.

Tip: In addition to providing support for the 32-bit versions of Windows, the 32-bit version of Office is supported on computers that run the 64-bit versions of Windows. Office 2010 lets users continue to use existing Microsoft ActiveX Controls, Component Object model (COM) add-ins, and Visual Basic for Applications (VBA). These are primarily 32-bit because no 64-bit versions are available for many add-ins.

If your organization needs to continue to use extensions to Office, such as ActiveX controls, third-party add-ins, in-house solutions built on previous versions of Office, or 32-bit versions of software that interface directly with Office, we recommend you go with the automatically installed 32-bit (x86) Office 2010 on computers that are running both 32-bit and 64-bit supported Windows operating systems.

You use 32-bit controls with no 64-bit alternative. You can continue to run 32-bit controls in 32-bit Office like Microsoft Windows Common Controls (Mscomctl.ocx, comctl.ocx), or any existing third-party 32-bit controls.

Your VBA code uses Declare statements. Visual Basic for Applications (VBA) that contain Declare statements won’t work in the 64-bit version of Office without being updated.

In SharePoint Server 2010 or earlier, the datasheet view won't be available. However, you can continue to use the Edit in Datasheet view functionality in SharePoint Server 2010 with a 32-bit Office client.

Compiled Access databases, like .MDE and .ACCDE files, won’t work unless they are specifically written for the 64-bit version of Office.

You need Legacy Equation Editor or WLL (Word Add-in Libraries) file in Word. You can continue to use Legacy Word Equation Editor (WLL files were deprecated in 32-bit and not supported in Office 2010).

There is no codec (software used to compress or decompress a video or audio file) available in 64-bit for three QuickTime media formats. Therefore, if you have an old embedded media file in a PowerPoint presentation, you’ll need to use 32-bit Office.